[Variant] XP cost with magic item creation

[theoremtank]

Say a PC wishes to have the local town wizard create for him a +1 longsword. Does there currently exist any variant rules where the PC would give up the required XP cost as opposed to the wizard.

The wizard might give the PC a discount in terms of gold price if the PC would give up a small amount of his essence (XP). What would some good in-game explanations be for such a house rule?

 

[Crothian]

In ELH there is a variant that allows people to share the XP cost

 

[der_kluge]

http://enworld.cyberstreet.com/showthread.php?s=&threadid=35741